1. Field of the Invention
The present invention relates to a silver halide photographic light-sensitive material and, more particularly, to a photographic light-sensitive material having improved photographic characteristics and storage properties and containing an emulsion containing tabular silver halide grains.
2. Description of the related art including information disclosed under 1.97-1.99:
Methods of forming and techniques of utilizing tabular silver halide grains are already disclosed in, for example, U.S. Pat. Nos. 4,434,226, 4,439,520, 4,414,310, 4,433,048, 4,414,306, and 4,459,353 and Japanese Patent Application (OPI) Nos. 59-99433 and 62-209445. The tabular silver halide grains have advantages such as improvements in sensitivity including an improvement in spectral sensitization efficiency obtained by a sensitizing dye, an improvement in a sensitivity/graininess relationship, an improvement in sharpness obtained by unique characteristics of the tabular grains, an improvement in covering powder, and the like.
However, a strong demand has arisen for a more advantageous photographic silver halide emulsion. That is, in addition to photographic characteristics such as sensitivity, and image quality such as graininess and sharpness, a higher level demand has arisen for so-called toughness such as an exposure intensity dependency, storage stability, and resistance to pressure. Conventional silver halide grains do not completely satisfy the above demand. Japanese Patent Application (OPI) No. 59-99433 discloses a technique for improving resistance to pressure of a light-sensitive material containing tabular silver halide grains having a grain diameter/thickness ratio of 5 or more. However, in this technique, exposure intensity dependency and storage stability of photographic characteristics cannot be completely improved.
This invention relates to a technique for controlling formation of dislocations in tabular silver halide grains. Dislocations of the silver halide grains are described in, for example, (1) C. R. Berry, J. Appl. Phys., 27, 636 (1956), (2) C. R. Berry, D. C. Skillman, J. Appl. Phys., 35, 2165 (1964), (3) J. F. Hamilton, Phot. Sci. Eng., 11, 57, (1967), (4) T. Shiozawa, J. Soc. Phot. Sci Japan, 34, 16, (1971), and (5) T. Shiozawa, J. Soc. Phot. Sci Japan, 35, 213 (1972). (1) to (4) describe that dislocations in grains can be observed by an X-ray diffraction method or can be observed directly by a transmission electron microscope at a low temperature and that a variety of dislocations can be generated in grains by intentionally applying stress to the grains. However, (1) to (4) do not describe that the technique for controlling formation of dislocations in tabular silver halide grains during a formation process of the grains is important to toughness as described above. (5) describes that dislocations can be observed in most of unsensitized tabular silver halide grains having a composition AgBrI (I=1 mol%) and a grain diameter/thickness ratio of 75 by a transmission electron microscope at a low temperature. However, (5) describes only observation of the individual grains but does not refer to a relationship between dislocation and the photographic characteristics at all. That is, overall photographic characteristics, of the grains, as an emulsion containing a large number of tabular silver halide grains having dislocations, are not examined at all.